Near infrared (NIR) optical imaging may provide the basis for a safe, noninvasive, transportable and relatively inexpensive device for functional brain imaging. Absorbtion by human tissue of light in the red and NIR wavelength regions is low enough that diffusively transmitted light can be collected from regions centimeters below the skin surface. The transmitted light may be used to obtain spatiotemporal information about the brain s optical properties, especially those properties that are known to be modified by the metabolic state of the brain (such as blood oxygenation) and by neuronal activity. The long-term objective of this project is the development of analysis and imaging software which will function as part of an instrument for NIR functional imaging, and support integration with other imaging modalities, such as MRI. During Phase I, prototype analysis and visualization software will be developed and tested. In addition, mathematical models of photon transport through tissue will be implemented as computer software, using finite element techniques. These calculations will be compared with results obtained from experimental measurements on a calibrated phantom. The successful completion of this preparatory work will lay the basis for the development and testing of image reconstruction software during Phase II. The result will be a novel and innovative product which has the potential to facilitate the development of basic and preclinical research in NIR imaging, with the possible future development into part of a clinical diagnostic imaging product. PROPOSED COMMERCIAL APPLICATION Research interest in NIR imaging is expanding and the proposed software may facilitate this growth by providing a useful product where none now exists. The resulting software will have direct application in preclinical and cogntive neuroscience research. If clinical value is demonstrated, systems based on this methodology may find applications in the areas of neurology and neurosurgery.